Determination of thiamethoxam residues and dissipation kinetic in tomato plants and its efficacy against Bemisia tabaci under open field eco system

Whitefly, Bemisia tabaci cause important losses for many crops especially tomato, therefore farmers often use many chemical insecticides which had dangerous side effects on human beings and environment, thus there are need to determine the residues of these chemicals in plant . The dissipation of thiamethoxam in tomato leaves and fruits followed the first order kinetics; Half-lives were 2.91 and 3.15 days for fruits and leaves, respectively. The residues of thiamethoxam were determined using a QuEChERS method with HPLC-DAD and it was 0.14 mg/ kg in fruits after 7 days of treatment and less than the maximum residue limit (MRL 0.2 mg/kg. The residue in leaves was more than in fruits. Seedlings produced from treated seeds were more resistant to different stages of the whitefly population and protect tomato plants from whitefly infestation for 6-10 weeks after transplanting. The three sprays of thiamethoxam increased the reduction percentage of B. tabaci stages and the highest increase was recorded after the third spray in egg, nymph, and adult stages. It could be recommend that Thiamethoxam is considered an unconventional insecticide appropriate for B. tabaci control and safe for humans and the environment.

Phase II study of apatinib in combination with oral vinorelbine in heavily pretreated HER2-negative metastatic breast cancer and clinical implications of monitoring ctDNA

OBJECTIVE

Apatinib is an oral TKI targeting VEGFR-2. Single-agent apatinib treatment has been shown to produce an objective response in patients with pretreated mBC. Oral vinorelbine also holds promise as a treatment of choice in patients with mBC. This study aimed to investigate the efficacy and safety of the oral vinorelbine-apatinib combination in patients with pretreated mBC. In addition, we detected gene variants in ctDNA to explore the therapeutic implications.

METHODS

This study enrolled patients with HER2-negative mBC who were pretreated with anthracycline/taxanes. Patients were treated with apatinib at 500 mg/425 mg daily plus oral vinorelbine 60 mg/m2 on days 1, 8, and 15 of every cycle (3 weeks). The primary endpoint was PFS. The secondary endpoints were ORR, CBR, OS, and safety. Patients eligible for ctDNA detection were evaluated before and during treatment.

RESULTS

Forty patients were enrolled. The median PFS was 5.2 months (95% CI, 3.4-7.0 months), and the median OS was 17.4 months (95% CI, 8.0-27.0 months). The ORR was 17.1% (6/35), and the CBR was 45.7% (16/35). The most common AEs included gastrointestinal reaction, myelosuppression, and hypertension. In 20 patients, ctDNA was detected at baseline and during treatment. A significant difference was found in PFS for undetected vs. detected baseline ctDNA (13.9 months vs. 3.6 months, P = 0.018).

CONCLUSIONS

All-oral therapy with apatinib plus vinorelbine displayed objective efficacy in patients with heavily pretreated HER2-negative mBC, with acceptable and manageable toxicity profiles. Patients with no gene variant detected and lower variant allele frequencies in ctDNA at baseline showed longer PFS.

Anthracycline-free or short-term regimen as adjuvant chemotherapy for operable breast cancer: A phase III randomized non-inferiority trial

Background

De-escalating anthracycline is gaining popularity for breast cancer patients. We aim to evaluate the non-inferiority of an anthracycline-free or short-term regimen to the standard anthracycline-based regimen for operable patients with human epidermal growth factor receptor 2 (HER2)-negative breast cancer.

Methods

It is a prospective, open-label, phase 3, randomized non-inferiority trial from June 1, 2010 to June 1, 2017. Follow-up had been kept until July 2019. This trial was conducted at Fudan University Shanghai Cancer Center. Patients with pT1-3N+ or pT2-3N0 but high-risk (grade II/III, lymphovascular invasion, ≤35 years of age or hormone-receptor negative) HER2-negative operable breast cancer were eligible and stratified by age, pathological tumour stage, pathological node status and hormone-receptor status. Patients were randomized to 6 cycles of docetaxel and cyclophosphamide (TC, n = 524), 3 cycles of cyclophosphamide/epirubicin/fluorouracil followed by 3 cycles of docetaxel (CEF-T, n = 523) or epirubicin and cyclophosphamide for 4 cycles followed by paclitaxel for 12 weeks (EC-P, n = 524) as the intention-to-treat population. Of these patients, 94% completed allocated therapy. Difference in disease-free survival (DFS) compared to EC-P. The prespecified non-inferiority margin was 4.5%, corresponding to the hazard ratio (HR) of 1.44 (one-sided α = 0.05), with an assumed 5-year DFS of 89% for EC-P.

Findings

Included in the intention-to-treat population were 1571 patients (median [IQR] age, 50 [45-57] years; 92% estrogen receptor [ER]-positive; 59% pN+). Through a median follow-up of 5.5 years, HR for TC versus EC-P was 1.05 (5-year DFS: 85.0% vs. 85.9%; 90% confidence interval [CI]: 0.79-1.39, non-inferior P = 0.048) and for CEF-T versus EC-P, 0.99 (5-year DFS: 85.1% vs. 85.9%; 90% CI: 0.75-1.30, non-inferior P = 0.045). Grade 3 or 4 adverse events for TC included rash (3.9%) and peripheral neuropathy (2.8%) and for CEF-T and EC-P diarrhea and nausea/vomiting were predominant. Results of per-protocol analyses were similar.

Interpretation

Both TC and CEF-T are non-inferior adjuvant regimen to EC-P mainly in patients with ER+HER2- breast cancer. TC is a safe regimen that avoids anthracycline-related side effects.

Funding

This work was supported by grants from the National Natural Science Foundation of China (Grants 81672600, 81722032, 82072916, and 91959207), the 2018 Shanghai Youth Excellent Academic Leader, the Fudan ZHUOSHI Project, the Municipal Project for Developing Emerging and Frontier Technology in Shanghai Hospitals (grant SHDC12010116), the Cooperation Project of Conquering Major Diseases in the Shanghai Municipality Health System (grant 2013ZYJB0302), the Innovation Team of the Ministry of Education (grant IRT1223), and the Shanghai Key Laboratory of Breast Cancer (grant 12DZ2260100) and the National Cancer Institute (grant P30 CA16058).

[Treatment of nevus of Ota and Ito and epidermal nevus syndrome]

Nevus of Ota, nevus of Ito and nevus of Hori are special melanocytic nevi that have a slate-brown or blue/grey coloring. They are pigmented disorders characterized by its heterotopic melanocytic dermal location and by blue/brown unilateral and sometimes bilateral facial patch in case of nevus of Ota, and in the supraclavicular, scapular, and deltoid region in case of nevus of Ito. It is more common in patients with Asian and dark-skinned ethnic backgrounds. Histologically, elongated, dendritic melanocytes are seen scattered mainly throughout the upper third of reticular dermis. An acquired variant is called Hori's nevus with more bilateral facial distribution, similar to melasma. Dermal melanocytosis can also occur elsewhere on the body, including inside the mouth. Despite its benign nature, patients frequently seek therapy because of its facial involvement. QS lasers are used effectively to treat these lesions. The number of treatment sessions correlates with clinical improvement. Post laser hypo- and hyperpigmentation are common side effects mainly affecting patients with darker skin.

Nano-encapsulation of a novel anti-Ran-GTPase peptide for blockade of regulator of chromosome condensation 1 (RCC1) function in MDA-MB-231 breast cancer cells

Ran is a small ras-related GTPase and is highly expressed in aggressive breast carcinoma. Overexpression induces malignant transformation and drives metastatic growth. We have designed a novel series of anti-Ran-GTPase peptides, which prevents Ran hydrolysis and activation, and although they display effectiveness in silico, peptide activity is suboptimal in vitro due to reduced bioavailability and poor delivery. To overcome this drawback, we delivered an anti-Ran-GTPase peptide using encapsulation in PLGA-based nanoparticles (NP). Formulation variables within a double emulsion solvent evaporation technique were controlled to optimise physicochemical properties. NP were spherical and negatively charged with a mean diameter of 182-277nm. Peptide integrity and stability were maintained after encapsulation and release kinetics followed a sustained profile. We were interested in the relationship between cellular uptake and poly(ethylene glycol) (PEG) in the NP matrix, with results showing enhanced in vitro uptake with increasing PEG content. Peptide-loaded, pegylated (10% PEG)-PLGA NP induced significant cytotoxic and apoptotic effects in MDA-MB-231 breast cancer cells, with no evidence of similar effects in cells pulsed with free peptide. Western blot analysis showed that encapsulated peptide interfered with the proposed signal transduction pathway of the Ran gene. Our novel blockade peptide prevented Ran activation by blockage of regulator of chromosome condensation 1 (RCC1) following peptide release directly in the cytoplasm once endocytosis of the peptide-loaded nanoparticle has occurred. RCC1 blockage was effective only when a nanoparticulate delivery approach was adopted.

Temperature Dependence of Absorption Spectra and Optical Parameters for Polyester Films of Dibenzylidene Cyclohexanone

Effect of temperature on the optical absorption spectra and optical parameters is investigated in new synthesized polyester films of poly[oxyiso-phthaloyloxy(2-methoxy- p-phenylene)methylidyne(2-oxo-1, 3-cyclohexanediylidyne)methylidyne(3-methoxy- p-phenylene)] (I) and poly[oxysebacoyloxy-(2-methoxy- p-phenylene) methylidene (2-oxo-1, 3-cyclohexanedi-ylidene)-methy-lidene-(3-methoxy- p-phenylene)] (II). Absorption measurements are carried out in the temperature range 80–370 K and in the photon energy range 1.9–4 eV. The optical absorption spectra of polymers I and II reveal excitonic absorption bands at 80 and 120 K respectively. These bands are associated with n →π* optical transitions along polymer backbone chains. Analysis of optical absorption data indicates that the Tauc equation for indirect optical transitions successfully explains the optical absorption process in polymeric film I, whereas Urbach’s law is more suitable for describing the optical absorption in polymeric film II. Temperature dependence of the optical bandgap, Eoptg, the Tauc slope √B, and the width of Urbach’s tail states ( Ee) exhibits anomalous parabolic behaviour which can be explained in terms of various current theories. Moreover, DSC, x-ray diffraction and morphological studies by TEM are used in the explanation of the experimental results. The values of optical parameters, as well as the temperature coefficient of the optical bandgap for these polymers, are calculated and reported.

Defining the Role of Neoadjuvant Chemotherapy Followed by Surgery in Locally Advanced Cancer Cervix: A Meta-analysis of Phase III Trials

STUDY OBJECTIVES

This meta-analysis was performed to compare the outcomes between NACT-S and RT for locally advanced cancer cervix. The primary end points were survival benefits.

SEARCHING METHOD

The data sources for the search included medline, national library of medicine, and the embase search engines. Inclusion criteria included studies published between 2000 and 2012, and FIGO stages IB2 to IVA. Studies had to be properly randomized, prospective, or retrospective and only phase III. Further, the studies had to be with two arms, including one arm for neoadjuvant chemotherapy then-surgery (NACT-S), and the other arm for radiotherapy (RT).

RESULTS

Data were collected from 1171 patients enrolled in seven phase III trials. The 5-year PFS (progression-free survival) for NACT-S and RT were 62 and 45.5 %, respectively. The 5-year OS for NACT-S and RT were 66 and 49 %, respectively. NACT-S was associated with better late toxicities compared to RT.

CONCLUSION

NACT-S is a reasonable treatment option for locally advanced cancer cervix. It achieved better results than RT, especially for stages from IB2 to IIB.

Weekly Paclitaxel Versus Three-Weekly Paclitaxel in Recurrent Platinum-Resistant Epithelial Ovarian and Peritoneal Cancers: A Phase III Study

INTRODUCTION

Treatment of recurrent platinum-resistant ovarian and peritoneal cancers represents a therapeutic challenge. The aim of this Phase III prospective study was to compare the survival benefits, objective response rate, and toxicities among patients treated by weekly paclitaxel with those who underwent three-weekly paclitaxel in recurrent platinum-resistant ovarian and peritoneal cancers.

METHOD

Patients with recurrent platinum-resistant ovarian and peritoneal cancer were allocated to receive either weekly paclitaxel (arm 1) at 80 m/m² or three-weekly paclitaxel (arm 2) at 175 mg/m².

RESULTS

Fifty-five patients were enrolled (30 arm 1, 25 arm 2). The mean age was 56.7 years, and the median performance status was 0 (Eastern Cooperative Oncology Group [ECOG]). For arms 1 and 2, the objective response rates were 27% and 16%, the median progression-free survival were 7 and 4.5 months, and the median overall survival were 15.5 and 12.5 months, respectively. Treatments also significantly improved the quality of life. Treatment was associated with mild toxicities, and while neuropathy was slightly higher for weekly paclitaxel over three-weekly paclitaxel, hematological toxicities were significantly lower for the former than the latter.

CONCLUSION

Paclitaxel rechallenge showed antitumor activity in recurrent platinum-resistant ovarian and peritoneal cancers. Weekly paclitaxel achieved better results than three-weekly paclitaxel in terms of survival benefits, quality of life, and toxicities.

Metronomic methotrexate and cyclophosphamide after carboplatin included adjuvant chemotherapy in triple negative breast cancer: a phase III study

BACKGROUND

Despite being chemosensitive, the majority of triple negative breast cancer (TNBC) patients recur. The primary study objectives were to compare disease free survival (DFS), and overall survival (OS) for TNBC after adjuvant chemotherapy, who underwent maintenance metronomic chemotherapy versus no maintenance therapy.

METHODS

TNBC patients were eligible for enrolment if they had TNM stages II-III and fit with our inclusion criteria. Patients were assigned to either: group 1, 3 cycles FEC-100 then 3 cycles docetaxel, carboplatin, followed by maintenance metronomic chemotherapy for 1 year; and group 2, 3 cycles FEC-100 then 3 cycles docetaxel.

RESULTS

Between November 2008 and December 2014, 158 patients (78 group 1, and 80 group 2) were enrolled. The mean age was 46 years. The median DFS for groups 1,2 were 28 and 24 months, respectively; P value 0.05. The median OS for groups 1,2 were 37 and 29 months, respectively; P values 0.04. Additionally, during the follow-up period, the overall distant metastasis recurrence rates for groups 1,2 were 26% and 37% respectively. Finally, treatment protocol was tolerated well in both groups with mild toxicity profiles.

CONCLUSIONS

Extended adjuvant metronomic chemotherapy achieved significant improvement in the survival and was well tolerated.

Obesity Correlation With Metastases Development and Response to First-Line Metastatic Chemotherapy in Breast Cancer

STUDY OBJECTIVES

To compare breast cancer metastases between obese and nonobese women and to evaluate the effect of first-line metastatic chemotherapy in each group.

METHOD

A retrospective study was performed in an educational institute in Ireland. The study consisted of two parts: the first part was a comparative analysis of metastases development in obese (arm A) and nonobese patients (arm B). The second part was a comparison between both arms in relation to their response to first-line metastatic chemotherapy and their survival data.

RESULTS

Between 2009 and 2014, we reviewed 118 patients with metastatic breast cancer. All the patients fulfilled our inclusion criteria. In all, 48% of patients were obese and 52% were nonobese. There were no statistically significant differences between the two groups. For arms A and B, the median interval between initial cancer diagnosis and distant metastases development (distant metastases-free survival) was 5.8 versus 7.6 years, respectively (Pvalue 0.04). Earlier visceral (liver and lung) metastases were observed in obese compared to nonobese women (Pvalues were 0.05 and 0.04, respectively). The most commonly used chemotherapy was weekly paclitaxel. Our treatments showed significantly better treatment response and better survival results in nonobese women than in obese ones, who were premenopausal with performance state 2, pathological grade 3, and four or more positive lymph nodes.

CONCLUSION

Obesity is linked with visceral metastases development, especially lung and liver metastases. Furthermore, first-line metastatic chemotherapy achieved better results in nonobese patients.

Neoadjuvant chemotherapy versus cystectomy in management of stages II, and III urinary bladder cancer

Purpose: This phase III trial was de - signed to compare the survival benefit, surgical respectability, and toxicities among patients treated by neoadjuvant chemotherapy followed by radical cystectomy (arm A), with those treated by radical cystectomy (arm B) in the management of stage II, III urinary bladder cancer. Patients and Methods: For inclusion, patients should have pathologically proven urothelial carcinoma in urinary bladder, clinical stages from T2N0M0 to T4aN0M0, patient age less than 65 years, and performance state ≤ 2. Additionally, patients should have adequate hematological, renal, and liver functions. Arm A patients underwent 3 cycles of neoadjuvant cisplatin and gemcitabine followed by radical cystectomy, while arm B patients underwent radical cystectomy directly. Results: Thirty patients had been enrolled in each arm between September 2009 and April 2014 in 3 educational institutes in Egypt. The 3 year OS (overall survival) for arm A, and B were 60% and 50% respectively. The median OS for arm A was 36+ months and that for arm B was 32.5 months. The 3 year progression-free survival (PFS) for arm A, and B were 57% and 43% respectively. The median PFS for arm A was 36+ months and for arm B was 28 months. A subgroup analysis was performed to correlate between 3 year OS and predetermined prognostic factors including age, tumor size, pathological stage, and the response to neoadjuvant chemotherapy. The later was performed only in arm A. Both treatment arms were tolerated well with mild toxicities profiles. Conclusion: Neoadjuvant chemotherapy achieved better survival, surgical respectability, with nearly equivalent toxicities when compared with radical cystectomy.

Temozolomide and Reirradiation in Recurrent Grade II Brain Glioma

BACKGROUND

This phase II trial was designed to assess the response rate, survival benefits and toxicity profile of temozolomide, and brain reirradiation using conformal radiotherapy (CRT) for recurrent grade II brain glioma. Between February 2006 and June 2009, 18 patients with recurrent low grade glioma, and two with recurrent ependymoma were enrolled in the study. Patients had to show unequivocal evidence of tumor recurrence on gadolinium-enhanced magnetic resonance imaging after failing conventional radiotherapy for initial disease.

METHODS

Patients were treated by temozolomide at a dose of 200 mg/m2/day for chemonaive patients, and at a dose of 150 mg/m2/day for previously treated patients, for 4 - 5 cycles. Then, patients underwent reirradiation by CRT at a dose of 30 - 40 Gy by conventional fractionation.

RESULTS

All the 20 patients were treated with temozolomide and reirradiation. Two patients achieved complete remission, and six achieved partial remission, with an overall objective response rate of 40%. The mean overall survival (OS) was 16 months (range, 6 - 24 months). The median OS was 15.5 months. Additionally, treatment significantly improved quality of life. Treatment was tolerated well with mild grade 1, 2 hematological toxicities, and nausea/vomiting in 15% and 39% of cycles, respectively.

CONCLUSIONS

Temozolomide and CRT had an anti-tumor activity in recurrent grade II brain glioma, and represented a good treatment hope for such patients.

Evaluation of protection in a mouse model after vaccination with Mycobacterium avium subsp. paratuberculois protein cocktails

Whole-cell vaccines successfully reduce signs of clinical disease and fecal shedding of Mycobacterium avium subsp. paratuberculosis (MAP), however, these vaccines have some limitations. The present study was conducted to identify MAP proteins that might be candidates for the development of an improved vaccine. MAP proteins were screened for immunogenicity in naturally infected cattle and selected based upon reactivity in the interferon-γ (IFN-γ) and Western blot assays. Proteins (MAP1087, MAP1204, MAP1272c, and MAP2077c) were arrayed into 4 overlapping cocktails containing 3 proteins each. The efficacy of the proteins within these cocktails as vaccine candidates was evaluated by subcutaneous immunization of mice, followed by challenge with live, virulent MAP. All MAP protein cocktails significantly reduced the recovery of live MAP from the ileum, while cocktails 1 and 3 reduced colonization in the liver. No significant differences were seen in the mesenteric lymph node or spleen, however, cocktail 1 reduced viable MAP in the mesenteric lymph node compared to other treatments. Stimulation of splenocytes upregulated antigen-specific IFN-γ and IL-23 secretion in all treatment groups, regardless of vaccination. Interestingly, IL-4 was moderately downregulated for vaccinates compared to control infected mice. An increase in total CD25 expression was noted for 3 of the 4 vaccinate groups upon stimulation of splenocytes with a whole cell sonicate of MAP, with this effect becoming more significant within CD4CD25+ and CD8CD25+ subpopulations. The present study demonstrated that MAP proteins are useful as vaccine candidates to reduce MAP tissue burden.

Chronic metabolic responses of postpartal dairy cows to subcutaneous glucagon injections, oral glycerol, or both

We examined the long-term effects of daily subcutaneous injections of 15 mg of glucagon during the first 14 d postpartum with or without coadministration of 400 mL of pure glycerol orally on blood metabolites and hormones and liver composition of Holstein dairy cows during early lactation. Fourteen multiparous cows with body condition score of >or=3.5 points (1-5 point scale) were assigned randomly to one of 4 treatment groups-saline, glucagon, glycerol, or glucagon plus glycerol. Fatty liver syndrome was induced by feeding cows a dry-cow ration supplemented with 6 kg of cracked corn daily during the last 6 wk of the dry period. Compared with saline treatment (n=3), coadministration of glucagon and glycerol (n=4) increased plasma glucose and insulin and decreased plasma nonesterified fatty acid concentrations in both treatment weeks, whereas glucagon alone (n=3) produced similar changes plus a decrease in plasma beta-hydroxybutyrate in the second week only. No significant changes were observed for the glycerol alone treatment (n=4). We conclude that a single daily dose of glycerol for the first 14 d postpartum may potentiate the action of glucagon in the first treatment days to alleviate some symptoms of fatty liver syndrome, such as the increase in plasma nonesterified fatty acids and the decrease in plasma glucose and insulin, in Holstein dairy cows after parturition.

Acute metabolic responses of postpartal dairy cows to subcutaneous glucagon injections, oral glycerol, or both

This study examined the effects of multiple subcutaneous glucagon injections with or without co-administration of oral glycerol on energy status-related blood metabolites and hormones of Holstein dairy cows in the first 2 wk postpartum. Twenty multiparous cows were fed a dry cow ration supplemented with 6 kg of cracked corn during the dry period to increase the likelihood of developing postpartal fatty liver syndrome. Cows with a body condition score of >or=3.5 points (1- to 5-point scale) were assigned randomly to 1 of 4 treatment groups: saline, glucagon, glycerol, or glucagon plus glycerol. Following treatment, serial blood samples were collected over an 8-h period to determine the effects of glucagon and glycerol on blood metabolites and hormones. Treatment effects were determined by comparing the concentrations of metabolites and hormones during the first 4-h period and the entire 8-h period after treatment administration (time 0) with the concentration of the same compounds at time 0 on d 1, 7, and 13 postpartum. Administration of glucagon alone increased concentrations of plasma glucagon and insulin on d 1, 7, and 13 and increased plasma glucose and decreased plasma nonesterified fatty acids (NEFA) on d 7 and 13 postpartum relative to the saline group. Administration of glycerol alone increased plasma glucose on d 7 and plasma triacylglycerols on d 1 postpartum. Glycerol administration also decreased plasma glucagon and NEFA on d 1, 7, and 13 and plasma beta-hydroxybutyrate (BHBA) on d 1 postpartum relative to the saline group. Administration of glucagon plus glycerol increased and sustained concentrations of plasma glucagon, glucose, and insulin on d 1, 7, and 13 and decreased plasma NEFA on d 1, 7, and 13 and BHBA on d 1 and 7. Early postpartal treatment of dairy cows with glucagon plus glycerol increased plasma glucose and insulin, decreased plasma NEFA and BHBA, and increased secretion of liver NEFA as plasma triacylglycerols. This suggests that glucagon and glycerol, when co-administered, act to decrease the likelihood of metabolism-related syndrome development in dairy cows.

Effects of chitosan on oxidative stress and metallothioneins in aquatic worm Tubifex tubifex (Oligochaeta, Tubificidae)

Chitosan is a natural polymer which has the property to elicit the natural defenses mechanism in plant and which can be an interesting biopesticides. It is then necessary to investigate the potential toxicity of chitosan for aquatic animal health. Metallothioneins (MTs) are low molecular weight proteins, mainly implicated in metal ion detoxification. Increase in MTs contents had been considered as a specific biomarker of metal exposure. However recently it has been demonstrated that MTs participate in several cellular functions such as regulation of growth and anti-oxidative defenses. Therefore, the induction of MTs has been investigated in the aquatic worms Tubifex tubifex exposed to chitosan. MTs levels in exposed worm increased significantly (p > 0.05) after 2, 4, and 7 days of exposure to different concentrations of chitosan (maximum + 158.19 +/- 10.2% after 2 days of exposure to 125 mgl(-1) of chitosan). Several antioxidant parameters including glutathione (GSH), glutathione-S-transferase (GST), glutathione reductase (GR), and catalase (CAT) were quantified in T. tubifex after 2, 4, and 7 days of exposure to chitosan. Exposure to chitosan had a negative effect on T. tubifex growth (maximum effect -6.11 +/- 1.6% after 7 days with 125 mgl(-1)) demonstrating the toxic effect of the pesticide. This growth rate decrease was accompanied by a reduction in protein contents. The activity of catalase (CAT), glutathione-S-transferase (GST), and glutathione reductase (GR) increased in response to the chitosan demonstrating an oxidative stress in the worms.

Intestinal absorption and presystemic disposition of sildenafil citrate in the rabbit: evidence for site-dependent absorptive clearance

Sildenafil citrate is the first oral treatment for erectile dysfunction. Its oral bioavailability is about 40%. This research investigated the intestinal transport parameters of sildenafil citrate in rabbit using an in situ intestinal perfusion technique. This was studied in four different anatomical sites, namely duodenum, jejunoileum, ascending colon and rectum. The results revealed the highest absorptive clearance in the jejunoileum. The values of the permeability area product normalized to segment length (ml/min.cm) were 0.0101, 0.0063, 0.0059 and 0.0023 and those of the percentage absorbed were 68.0, 32.3, 23.0 and 5.0 in jejunoileum, duodenum, ascending colon and rectum, respectively. The values of the length (cm) required for complete absorption were 87.6, 137, 153 and 384 for each anatomical site in the same order. The absorptive clearance did not correlate with the net water flux in the four anatomical regions studied, indicating a mainly passive diffusion mechanism through a transcellular pathway. The plasma sildenafil concentrations achieved during intestinal perfusion experiments and sildenafil total body clearance in the rabbit were used to calculate the fraction of sildenafil that reached the systemic circulation relative to the amount that disappeared from the intestinal segment. Only 34% of sildenafil that disappeared from the intestinal segment appeared in the systemic circulation indicating that the presystemic elimination of sildenafil is 66%. These results confirm that the incomplete bioavailability of sildenafil is mainly due presystemic elimination.

Determination of the Cation-Exchange Capacity of Muscovite Mica

High cation-exchange capacity (CEC) muscovite mica with a homoionic surface was prepared by replacing the Li(+) surface ions of partially delaminated Li-mica with K(+). The CEC of this K-mica was determined by exchanging its surface cations with Cs(+), NH(+)(4), methylene blue (MB(+)), and copper triethylenetetramine [Cu(trien)(2+)]. The kinetics of these exchange reactions were studied and showed large differences depending on their relative affinities to mica. The NH(4)(+)/K(+) exchange was slow, while the Cs(+) and Cu(trien)(2+)/K(+) exchange was fast. The MB(+)/K(+) exchange was quite slow and was not completed even after 99 h. Insufficient reaction time is one of the main reasons for the contradictory results reported in the literature for the CEC of aluminosilicates obtained by different methods. The CEC of mica can be photometrically measured by exchanging its surface cations with Cu(trien)(2+). Copyright 2000 Academic Press.

Dodecyl Pyridinium/Alkali Metals Ion Exchange on Muscovite Mica

Model muscovite with high cation exchange capacity was prepared, the surface of which was saturated with a single species of alkali metal ions. The kinetics and thermodynamics of the exchange reaction of the 1-dodecylpyridinium ion (NDP+) with alkali metal ions onto that substrate were studied. The exchange rate depended on the type of alkali metal ions present on the surface because of their different affinities to mica. However, in all cases the reaction was fast at the beginning and about 50% of the ions were exchanged within one hour; then the reaction rate decreased and equilibrium was only reached after several hours. This was attributed to a rate-determining rearrangement step in which the alkyl chains rearrange to adopt a dense packing. The reactivity of the alkali metal ions was in the order Li+ > Na+ > K+ > Rb+, Cs+, and in the case of K+, Rb+, and Cs+, equilibrium was only reached after 72 h. The lithium and sodium ions were exchanged almost quantitatively until a saturation value was nearly reached, while the K+, Rb+, and Cs+ exchange isotherms were less steep. The equilibrium constants (K) as well as the ion exchange capacity (S) were calculated by least-squares fits. Since K is infinite for quantitative exchange and decreases asymptotically upon deviation from this ideal behavior, the high K values (>10) of the NDP+/Li+ and Na+ exchange cannot be accurately determined. K ranges between 1 and 3 for the NDP+/K+, Rb+, and Cs+ exchange. The affinity of NDP+ to muscovite was similar or slightly higher than that of K+, Rb+, and Cs+, but was much higher than that of Li+ and Na+. The presence of oxonium ions in water did not strongly influence the exchange reaction on delaminated mica, as in the case of mica sheets, due to its high CEC. Copyright 1999 Academic Press.

Alkali Metals Ion Exchange on Muscovite Mica

The lithium surface ions of a muscovite, which was partially delaminated with a hot saturated lithium nitrate solution, exchange readily with sodium, potassium, rubidium, and cesium ions. The remaining potassium ions in the interlayers of the muscovite do not exchange at ambient conditions. The surface ion exchange is quite fast but can be followed by measuring the change in conductivity of the reaction mixture. In dilute systems, an initial drop in conductivity due to the exchange of the alkali metal ions with Li+ was observed, which was followed by a slow increase over a long period of time. That increase in conductivity is attributed to the formation of alkali bicarbonates due to the CO2 omnipresent in water. The surface Li+ was exchanged almost quantitatively by K+, Rb+, or Cs+ until a saturation value was nearly reached, while the Li+/Na+ exchange was less quantitative. The equilibrium constants (K) of these reactions as well as the ion exchange capacity were calculated by nonlinear least-squares fits. For the Na+/Li+ exchange K was found to be 4, while those of the K+, Rb+, and Cs+ exchange were too high for an accurate determination. The affinity of the alkali metal ions to muscovite decreased in the order K+, Rb+, Cs+ > Na+ > Li+. Copyright 1999 Academic Press.

Iqg1p, a yeast homologue of the mammalian IQGAPs, mediates cdc42p effects on the actin cytoskeleton

The Rho-type GTPase Cdc42p has been implicated in diverse cellular functions including cell shape, cell motility, and cytokinesis, all of which involve the reorganization of the actin cytoskeleton. Targets of Cdc42p that interface the actin cytoskeleton are likely candidates for mediating cellular activities. In this report, we identify and characterize a yeast homologue for the mammalian IQGAP, a cytoskeletal target for Cdc42p. The yeast IQGAP homologue, designated Iqg1p, displays a two-hybrid interaction with activated Cdc42p and coimmunoprecipitates with actin filaments. Deletion of IQG1 results in a temperature-sensitive lethality and causes aberrant morphologies including elongated and round multinucleated cells. This together with its localization at the mother-bud neck, suggest that Iqg1p promotes budding and cytokinesis. At restrictive temperatures, the vacuoles of the mutant cells enlarge and vesicles accumulate in the bud. Interestingly, Iqg1p shows two-hybrid interactions with the ankyrin repeat-containing protein, Akr1p (Kao, L.-R., J. Peterson, J. Ruiru, L. Bender, and A. Bender. 1996. Mol. Cell. Biol. 16:168-178), which inhibits pheromone signaling and appears to promote cytokinesis and/or trafficking. We also show two-hybrid interactions between Iqg1p and Afr1p, a septin-binding protein involved in projection formation (Konopka, J.B., C. DeMattei, and C. Davis. 1995. Mol. Cell. Biol. 15:723-730). We propose that Iqg1p acts as a scaffold to recruit and localize a protein complex involved in actin-based cellular functions and thus mediates the regulatory effects of Cdc42p on the actin cytoskeleton.

Bromfenac, a new nonsteroidal anti-inflammatory drug: relationship between the anti-inflammatory and analgesic activity and plasma drug levels in rodents

Bromfenac [2-amino-3-(4-bromobenzoyl)benzenacetic acid, sodium salt sesquihydrate] exhibited potent analgesic and anti-inflammatory activity in mice and rats. In a mouse model of pain (acetylcholine abdominal constriction), bromfenac showed a rapid onset of activity (20 min) that persisted for at least 4 hr. In a rat model of inflammation (carrageenan foot edema), a single oral dose of bromfenac, 0.316 mg/kg, produced significant anti-inflammatory activity up to 24 hr after dosing. Bromfenac was readily absorbed after oral administration, peak plasma levels being achieved at the earliest time tested: 20 min in the mouse and 30 min in the rat. The plasma half-life of bromfenac in rats is less than 4 hr. Since the anti-inflammatory activity persisted for 20 to 24 hr in spite of its short plasma half-life, it appears that there is no direct correlation between duration of activity and plasma drug level.

Pharmacodynamics and pharmacokinetics of AHR-11748, a new antiepileptic agent, in rodents

AHR-11748, the desmethyl metabolite of fluzinamide (an effective antiepileptic), was active in preventing maximal seizures induced in mice or rats by electroshock and threshold seizures induced in mice by Metrazol, bicuculline, and picrotoxin. The compound showed a profile of anticonvulsant activity similar to those of phenobarbital and valproic acid and different from those of phenytoin and ethosuximide. ED50s were less than those of valproic acid, but greater than those of phenobarbital. Analysis of plasma and whole brain homogenates of mice indicated that AHR-11748 has an apparent terminal half-life (t1/2, beta) of 1.0 h. The brain:plasma ratio of AHR-11748 was 3.4:1 from 0.5 h to 6 h.

Peripheral neural involvement in cutaneous leishmaniasis. A pathologic study of human and experimental animal lesions

Peripheral neural involvement in cutaneous leishmaniasis has recently been recognized. A man presented with several tender hyperesthetic skin nodules. Histopathologic examination confirmed the diagnosis of cutaneous leishmaniasis. Of most interest was the presence of a striking lymphohistocytic inflammatory infiltrate around and within cutaneous nerves in addition to demonstrable leishmania organisms in the perineural space. This observation led to a detailed histopathologic evaluation of leishmanial skin lesions that developed in 13 mice after subcutaneous injection with leishmania major promastigotes. Varying degrees of neural involvement was noted in skin lesions from nine animals. In some lesions, in addition to inflammatory cells in the nerves, organisms were demonstrable within probable schwann cells. Three pathologic stages of dermal neural involvement were identified, namely, an early, intermediate, and late stage, depending on the severity of damage; however no correlation was found between the pathologic stage and the duration of the leismanial skin lesion of a specific animal.

Liquid chromatographic quantitation of chicken and turkey in unheated chicken-turkey mixtures

A simple and rapid liquid chromatographic (LC) method has been used to quantitate chicken and turkey in unheated chicken-turkey mixtures. The LC method is sensitive and detects as little as 1% chicken or turkey. It reliably quantitates 5-100% chicken or turkey in unheated poultry mixtures. The method applies also to chicken or turkey which has been frozen, but does not apply to heat-treated poultry meats.

Simultaneous determination of fluzinamide and three of its active metabolites in plasma by high-performance liquid chromatography

A sensitive and selective high-performance liquid chromatographic method has been developed for a new anticonvulsant, fluzinamide, and three of its active metabolites. This method requires only 0.5 ml of plasma, and it involves a single extraction with a mixture of hexane--dichloromethane--butanol (55:40:5). The plasma extract is chromatographed on a 10-micron, C18 reversed-phase column and quantitated by ultraviolet absorbance at 220 nm. The concentration--response curves for all four compounds are linear from 0.05 micrograms/ml to at least 10 micrograms/ml. The extraction efficiency of this method is greater than 90%. The accuracy and precision of the method were tested by analyzing spiked unknown samples that had been randomly distributed across the concentration range. The mean concentrations found were within +/- 9% of the various amounts added with a standard deviation of +/- 3.5%. This method has been successfully applied to the analysis of samples obtained from fluzinamide-dosed dogs, healthy unmedicated volunteers, and patients who were at steady state with phenytoin, carbamazepine, and fluzinamide.

Reduction in oral penicillamine absorption by food, antacid, and ferrous sulfate

Plasma levels of penicillamine, urinary recovery of penicillamine and its oxidized metabolites, and urinary excretion of copper were examined after single 500-mg oral doses of penicillamine to six healthy men. Penicillamine was given after an overnight fast, a standard breakfast, and after antacid and ferrous sulfate. Following the fasting dose, the mean peak plasma level of 3.05 micrograms/ml developed at 3.8 hr and the drug was cleared from plasma with a t1/2 of 2.1 hr. Penicillamine levels were reduced to 52%, 35%, and 66% of those from the fasting dose after food, ferrous sulfate, and antacid. The rates of penicillamine appearance and disappearance from plasma were essentially treatment independent. There were good correlations between urinary recovery of total penicillamine (r = 0.875), between urinary copper excretion (r = 0.758) and the penicillamine plasma concentration AUCs. The availability of oral penicillamine is very susceptible to interactions with other substances. Further studies may be necessary to assess the full clinical significance of these interactions.

Influence of food on the bioavailability of penicillamine

The relative bioavailability of D-penicillamine was determined after single 500 mg oral doses of commercial tablets to healthy male volunteers under fasting and nonfasting conditions. In fasted individuals the mean maximum penicillamine level in plasma of 3.05 mcg/ml occurred at 3.8 h, and the area under the 0-12 h plasma curve was 14.7 mcg/h/ml. In nonfasted individuals the mean maximum penicillamine level of 1.52 mcg/ml occurred at 2.3 h, and the area under the 0-12 h plasma curve was reduced to 7.16 mcg/h/ml. Thus under these conditions food reduced systemic penicillamine availability by 1/2, but did not reduce the apparent absorption rate.

Absorption of theophylline from enteric coated and sustained release formulations in fasted and non-fasted subjects

The influence of prior food ingestion, and also of varying fluid volumes, on plasma theophylline levels was examined following single oral doses of two sustained-release formulations, Theobid (260 mg) and Theo-Dur (200 mg) and one partially enteric-coated formulation, Choledyl (128 mg), to 9 healthy volunteers. Prior food ingestion tended to delay the absorption of theophylline from all formulations to a small extent. This effect was observed only at early sampling times, and plasma drug profiles were similar for all treatments within a particular formulation. Theobid and Theo-Dur gave rise to plasma profiles that were characteristic of sustained-release formulations, with mean Cmax values of 5.5-5.7 micrograms ml-1 (Theobid) and 2.8-3.2 micrograms ml-1 (Theo-Dur) occurring at 5.8-9.1 h after dosing. Choledyl gave rise to a longer absorption lag time than the other formulations but was subsequently absorbed at a faster rate yielding mean Cmax values of 3.2-3.5 micrograms ml-1 at 2.8-4.1 h. The intersubject variability in theophylline plasma levels, and also in most pharmacokinetic parameter values, was generally less following Theo-Dur compared to the other formulations.

Bioavailability of chlorothiazide from 50, 100, and 250 MG solution doses

The bioavailability of chlorothiazide was examined following single oral solution doses to eight healthy male volunteers. Drug was administered in 250 ml of water after overnight fast. Bioavailability was determined by measuring 72 h urinary recovery of unchanged drug. Mean urinary recovery from 50, 100, and 250 mg doses was, respectively, 28.3, 47.0 and 83.3 mg, representing 56.4, 47.0, and 33.3 per cent of the administered dose. The correlation coefficient between dose size and percentage recovery was -0.662. These results add support to previous suggestions that the absorption of chlorothiazide from the gastrointestinal tract is saturable, and that the availability of chlorothiazide may be similar to that of hydrochlorothiazide when these compounds are administered in the same dosage range.

Organic contaminates in water

The carbon adsorption method was used for separating organic matter from large samples of drainage, river and tap water. The carbon chloroform extract (CCE) was separated into different solubility fractions and the neutral fraction was separated into aliphatic, aromatic and oxy-compounds using column chromatography. The aromatic fraction was subjected to TLC, IR and UV analysis. The pesticide endrin was present in both river and tap water at concentrations of 0.7 and 1.5 ppb, respectively.

Persistence of carbaryl in canal water

The presence of the insecticide carbaryl (Sevin) and its decomposition product 1-napthol was confirmed in irrigation and drainage canal water. However, their residues disappeared from the water 6 days after application.